1. Field of the Invention
The present invention relates to a machine frame for supporting at least one dewatering element over which an endless belt travels during operation of a papermaking machine.
2. Description of the Related Art
Machine frames of this type are present, in particular, in paper manufacturing machines. The dewatering element may be a roll, for instance a dewatering suction roll or a press roll, or else, for instance, a stationary suction box. In each case, an endless belt, for instance a wire belt or a felt belt, travels upon operation over the dewatering element. The invention can therefore be used in particular in the wire end or the press end of a papermaking machine.
A prior art machine frame of background interest has the following features:
a) the dewatering element has an operator-side end and a drive-side end; PA1 b) a beam which extends substantially parallel to the dewatering element is connected in torsionally rigid manner; PA1 b1) to a first frame part for supporting the drive-side end of the dewatering element which rests in tilt-proof manner on a foundation; PA1 b2) and to a second frame part for supporting the operator-side end of the dewatering element which rests on the foundation via removable intermediate pieces; and PA1 c) an extension of the beam extends beyond the operator-side frame part, the outer end of the extension being adapted to rest on the foundation.
These features are known from Federal Republic of Germany OS 32 42 721 (File P 3983). This publication concerns a roll press having two press rolls which form a press nip with each other. The ends of the lower press roll rest on lower frame parts. In the same way, the upper press roll rests on upper frame parts. On the drive-side end, the frame parts are rigidly connected with each other to form a frame. On the other hand, on the operator-side end, the frame parts are connected to each other by tension elements which serve to transmit the pressing force from the upper frame part to the lower frame part. The tension elements can be loosened in order, for instance, to replace the endless belt which travels around the lower press roll with a new felt belt. In addition, the following features are provided for this purpose: The operator-side lower frame part, in normal condition of operation, rests on the foundation via two removable intermediate pieces. A beam (59) connects this frame part to the drive-side frame. On the outer side of the drive-side lower frame part, there is provided an auxiliary support (58) which forms an extension of said beam and which can also be supported on the foundation, for instance via a removable intermediate piece (60). Furthermore, two beams (29) are provided in order to connect the upper operator-side frame part with the drive-side frame. These beams are fastened in torsionally rigid manner to the frame parts.
One disadvantage of this known machine frame is its relatively large size. This results, among other things, from the fact that the lower beam (58) is arranged below the upper press roll and furthermore from the fact that two upper beams (29) are necessary and that they are arranged above the upper press roll. Finally, the transmission of the pressing force from the upper frame part to the lower frame part requires a relatively heavy construction.
Federal Republic of Germany Utility Model 91 12 587 (File P 4876) discloses another roll press in which the bearing brackets of the two press rolls are connected directly by means of detachable tie bars which serve for the transmission of the pressing force. This manner of construction may cause the machine frame to be acted on only by the weight of the press rolls themselves but not by the pressing force. Therefore, the machine frame may possibly be made substantially lighter. However, no further details are disclosed in this German Utility Model.
The disclosures of the above-mentioned references are expressly incorporated by reference herein.